Electric shock while playing on guitar - need HELP !

Hi ive got quite a big problem and i need help.I played on my guitar which was connected to my external sound card M-Audio fast track Mk. II, a then when i was finnished playing i touched to guitar connector and i got really big electric shock. When i started to play i didnt get any shocks.Can somebody please tell me what could be a problem ? Im using laptop lenovo Ideapad Y550p.

Yea, so its wrong outlet. I tried to play on guitar with only battery in laptop for long time and i didnt get any shock. Well im living in quite old house, so this is probably the problem. I will call an electrician.Thank you very much for that advice with battery, much appreciated